9403 speed measurement possible?

[iyeager]

Tried this in the software forum, was thinking it's probably a hardware question.

I'm trying to measure the speed of a shaft (spinning at ~10,000 RPM) using Labview 10, a CDaq-9188, a 9403 module, and a hall-effect prox sensor. While trying to configure the DAQAssistant it says that the 9403 module cannot buffer signals for continuous sampling. Is there a way to measure shaft speed using this setup, or am I going to have to give up one of my 9243 channels and run with AC coupling, as this post suggests;

http://forums.ni.com/t5/Measure/speed-or-velocity/​m-p/1100360#M693

A snippet of code would help too, I'm learning still.

-Ian

[Michelle_N]

I think the main question is what signal does your sensor provide - looks like it must be some kind of digital signal. Can you give us more information about the signal itself?

I might suggest taking a look at the examples we have for the 9403 - this will give you a good idea of what kind of tasks you can do with the module. In LabVIEW go to Help > Find Examples...

At the bottom of this page you will find a drop down labeled Hardware. Select Add Device and add the 9403 and click OK. Then you'll have to select the 9403 from the drop-down and place a check mark in the Limit results to hardware. Now all the examples will be only examples that will work with the 9403.

[iyeager]

The signal is from a hall effect sensor that's reading a keyway off of a shaft. I think I've found an example that I will be able to adapt to the project and utilize the PFI on the chassis. I will update after and let everyone know if it works.

Also, in case anyone stumbles upon this thread later, according to the AE at NI, the 9403 cannot be used to interface with the 4 onboard counters on the 9188 chassis. I'm sure it has to do with the available extra pin-outs on a 4- or 8-channel DIO card vs. a 32-channel DIO card.

-Ian

[Seth_B.]

To clarify, the issue with using the NI 9403 for counter based measurements stems from the fact that the NI 9403 is a software timed digital module, not hardware timed.  You will need a hardware timed digital module such as the NI 9401 or 9402 (and a few others) in order to use the counters.  Because of the CompactDAQ architecture, hardware timed modules can only have up to 8 lines per module.

[iyeager]

Any idea on how to setup the 9188 to perform a counter task using the PFI? I tried to use MAX/Neighborhood/Create... but it says that it does not detect hardware capable of doing it. MAX does find the chassis, and my LabVIEW program has already acquired and sent data using modules in this chassis so I know the connections good.

-Ian

[MarkGrot]

You cannot use the DAQ Assistant with internal channels.

As posted in your other thread:  here